Plastic piston pump

ABSTRACT

A piston displacement pump capable of elevating a column of water or the like from a source of supply situated below the locale of the embedded pump and delivering the same, against the forces of gravity, to a usable level. A pump which is unique, in part, in that all of the principal component parts are made of economical polyvinyl chloride or equivalent commercial plastics. This pump comprises a cylindrical barrel which serves as the cylinder, an attached ball check inlet valve, and a reciprocatable plunger. The plunger embodies an axially bored piston, a coacting stem or rod, and a valved operating connection between the piston and its actuating rod.

United States Patent Fitzgerald et a1.

[54] PLASTIC PISTON PUMP [72] Inventors: Donal T. Fitzgerald, 882 W. Rocky St., Raymondville, Tex. 78580; Jack S. Campbell, Armstrong Ranch, Armstrong, Tex. 78338 22 Filed: Sept. 29, 1970 211 Appl.No.: 76,365

US. Cl ..417/554 [51 1 Int. Cl. .F04b 21/04, F04b 39/10 [58] Field 01 Search .4l7/354, 555, 545, 547, 552, 417/548 [56] References Cited UNITED STATES PATENTS 780,518 l/1905 Miller ..417/554 1,497,541 6/1924 Camblin ..417/554 1,831,411 11/1931 Dietz ..417/554 2,026,058 12/1935 Perry ..417/554 l/IIIIII 51 Aug. 15,1972

AttorneyClarence A. O'Brien and Harvey B. Jacobson [57] ABSTRACT A piston displacement pump capable of elevating a column of water or the like from a source of supply situated below the locale of the embedded pump and delivering the same, against the forces of gravity, to a usable level. A pump which is unique, in part, in that all of the principal component parts are made of economical polyvinyl chloride or equivalent commercial plastics. This pump comprises a cylindrical barrel which serves as the cylinder, an attached ball check inlet valve, and a reciprocatable plunger. The plunger embodies an axially bored piston, a coacting stem or rod, and a valved operating connection between the piston and its actuating rod.

3 Claims, 3 Drawing Figures PLASTIC PISTON PUMP This invention relates to a pump which is characterized by a well pipe or barrel which is provided at its lower end with a foot-type ball check inlet valve and wherein a novel valve-equipped plunger is mounted for reciprocation in the bore of the barrel and also wherein the barrel constitutes the necessary column lifting cylinder and the plunger features significant improvements hereinafter set forth.

One aspect of the inventive concept as will be hereinafter more fully appreciated has to do with a pump construction wherein the principal relatively movable component parts are constructed of moldable, plastic materials. However, and for background purposes, it can be pointed out that the idea of constructing pump components from commercial plastics of varying grades is not, broadly speaking, new. For example, an all plastic pump, structurally unlike the present invention, is disclosed in a patent to Earl L. Sisson, U.S. Pat. No. 3,006,282.

In carrying out the principles of the present invention the preferred embodiment has to do with a structural arrangement wherein a plastic or a synthetic pipe or barrel serves not only as the well casing but also as the cylinder of the pump. The use of this pipe or barrel, as the cylinder, obviates the need for customarily used brass or copper liners and the like which function as piston cylinders. To the ends desired, the instant adaptation constitutes an improvement over prior art pumps in that the overall structure weighs less, cost less to manufacture, install and use and works with reliable efficiency. Experience has also shown that it will involve less expense to move and service the well and the pump therein. One pump experimentally in use employs polyvinyl chloride with success but other and various types of plastic and vinyl pipes and barrels can be successfully used.

Briefly the well or equivalent pump under advisement comprises an elongated cylindrical barrel which provides a fluid column confining and elevating cylinder. This barrel has a lower intake end provided with an attached foot valve, more particularly, an apertured cup-like assembly which is screwed into the screw-threaded lower end of the barrel and provided with a captive ball check valve. A plunger is mounted for reciprocation manually or by power in the cylinder. The plunger is unique in that it embodies a fluid column lifting piston which is slidingly operatively confined in the bore of the barrel, said piston being actuated by a coacting rod which is suitably reciprocably mounted in the cylinder. The piston has an axial bore which extends therethrough and provides a fluid passage, more particularly, one which is open at its lower inlet end and also open at its upper discharge end. Valve means is mounted on the upper end of the piston. This valve means is communicable with the upper end of the passage and the lower end of the piston rod is operatively united with the valve whereby the valve provides an operating union or joint between the rod and piston.

The piston is of a transverse cross-sectional dimension so that the outside diameter is just slightly less than the inside diameter of the bore of the barrel and has its peripheral surface in direct fluid-tight wiping contact with the encompassing wall of the barrel in a manner that there is no need to provide the peripheral surface of the piston with packing rings, such as are ordinarily required to assure a fluid-tight seal.

The concept also features a construction wherein the entire lower end of the piston is provided with a cavity or recess. This recess is proportional or dimensional with the cross-section of the bottom of the piston and is conical in form. It has its upper truncated apical end merging communicatively into the coacting lower end of the axial bore and accordingly provides a funnel-like pocket. This pocket is adapted to trap and guide the sand-laden and equivalent water or fluid into and for elevating passage through the bore in a manner to minimize wear and tear on the cylinder and piston surfaces.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a view in side elevation with a portion broken away showing the barrel, plunger and foot valve mounted at the lower end of the barrel.

FIG. 2 is an enlarged detail view which shows the construction and coordinating relationship of the coacting component parts.

And FIG. 3 is a cross-section taken on the plane of the section line 3-3 of FIG. 1.

Referring now to the several views of the drawing with the aid of identifying reference numerals, it will be seen that the plastic or equivalent pipe or barrel is denoted, generally stated, by the numeral 6. This barrel is of requisite cross-section and length, say 20 feet or so, the lower end thereof being denoted at 8 and being internally screw-threaded at 10. The median or body portion is denoted at 12. The upper end portion is denoted at 14 and may terminate in any suitable construction (not detailed). The hollow bore of this barrel is denoted at 16 and constitutes a cylinder for the reciprocable plunger 18. Before discussing the plunger it is to be mentioned that the fluid or water inlet foot valve is denoted at 20 and comprises a plastic cup-like member 22 whose upper end portion 24 is externally screw-threaded and screwed into the aforementioned threads 10 as brought out in FIGS. 1 and 2. The bottom of the cup is provided with an intake port or orifice 26 and the interior bottom surface 28 provides a seat for a suitable ball check valve 30 which is captive in the receptacle portion 32 and is confined against displacement by an appropriate retaining pin 34.

The aforementioned plunger is characterized, as already suggested, by a solid elongated piston 36 which is made of suitable plastic material and which is provided with an axial openended bore 38. The lower end portion 40 of this piston is provided with a conical, more particularly, a truncated conical recess 42 which provides a water-piloting and directing pocket, the truncated or apical end 44 being communicatively joined with the open lower end portion 46 of the bore or passage. The upper open end of the passage is denoted at 48 and there is a counterbore provided above this which is internally screw-threaded at 50 to accommodate a screw-threaded lower end portion 52 of a specially constructed plastic fitting, more particularly a fitting 54 which is also of inverted cup-like form and has an upper body portion 56 which is provided with a screw-threaded bore 58 for reception and retention of the screw-threaded shank 60 of the reciprocable piston rod 62. The hollow portion of this fitting or connector 54 has its wall provided with discharge orifices or ports 64, said hollow portion serving to accommodate the ball check valve 66.

The piston 36 preferably comprises a solid piece of suitable plastic material which is formed to fit the bore or cylinder 16. This piston can be milled or it can be molded or shaped by other means so as to provide the proper close fit within the encompassing bore or cylinder. The bore or hole is drilled or otherwise provided as at 38 for the water to flow through. T he foot valve provides the desired automatically functioning inlet valve assembly. The means 54 provides not only the desired ball check feature but provides a coupling between the lower end of the rod 62 and the upper cooperating end portion of the piston 36. The bottom or base of the piston is recessed or hollowed out to provide the desired funnel whereby to guidingly direct the water to the center, thereby reducing wear and tear on the piston and cylinder.

Experience has shown that the invention is possessed of the desired lightness in weight. It embodies simplicity in construction of the component parts and is less costly to use then copper and brass. Then, too, the servicing cost is less since one man can pull out the light weight plunger assembly and service the same. Experience has shown that chemicals, salty water or abrasive materials can be pumped with this unique pump construction. it should also be noted that no leather is used in the pump. Further, the length of the stroke can be much longer than on conventional pumps. Location of the piston can be raised or lowered and when there is wear in one place, another surface can thus be made available for equal distribution of wear. The pump can be used for either deep or shallow wells and any source of pump actuating power (not shown) can be used. Furthermore, the materials which have been adopted and used and revealed herein reduce friction and make the pump work with reliable efficiency.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A pump comprising an elongated cylindrical barrel providing a fluid column confining and elevating cylinder, said barrel having a lower intake end provided with an attached foot valve, a plunger mounted for reciprocation in said cylinder, said plunger embodying a fluid column lifting piston slidingly operatively confined in the cylinder, a piston actuating rod reciprocable in said cylinder, said piston having a uniform axial bore extending therethrough and providing a fluid passage and being open at its lower inlet end and also at its upper discharge end, and a column lifting valve operatively mounted on the upper end of said piston, said lifting valve bemg communicable with the upper end of said passage, the lower end of said rod being operatively united with said lifting valve, and said lifting valve providing an operating joint between the rod and piston, said piston being of a transverse cross-sectional dimension that the outside diameter is just slightly less than the inside diameter of the bore of said barrel and has its peripheral surface in wiping contact with the encompassing wall of said barrel, whereby to obviate the need for packing rings on said peripheral surface, the entire lower end of said piston provided with a recess, said recess being truncated conical in form having its upper truncated apical end merging communicably into the coacting lower end of said bore and providing a funnel-like pocket means for trapping and guiding a sand-laden fluid into said bore for passage therethrough and, in so doing, to minimize wear and tear on the cylinder and piston surfaces.

2. The pump defined in and according to claim I, and wherein said barrel, plunger and the operating joint are individually made of coacting plastic material.

3. A pump comprising an elongated cylindrical barrel made of plastic material, the bore of said barrel providing a fluid column confining and elevating cylinder, said barrel having a lower end, an inlet valve assembly constituting a foot valve and removably fitted into and secured in place in said lower end, said valve embodying a plastic cup provided with an inlet orifice and having a captive ball check valve in the receptacle portion of the cup, a plunger mounted for receiprocation in said cylinder, said plunger embodying a plastic piston slidingly and operatively confined in the cylinder, also having a fluid passage, further having a reciprocating rod operable in the barrel .bore, a coupling interposed between and connected to the rod and an upper end of the piston and having discharge ports and a hollow portion confining a ball check valve, said piston being elongated with its peripheral surface in sliding wiping contact with the wall of said cylinder and having a uniform axial open-ended bore comprising the fluid passage, the piston bore being open at its upper and lower ends, the upper end providing a seat, and the adjacent ball check valve being cooperable with said seat, and the lower end of said piston being provided with a truncated conical recess, the larger end of said recess opening through the bottom of said piston, the truncated upper end of said recess being communicable with the lower end portion of said bore and providing a funnel-like pocket means for trapping and guiding a sand-laden fluid into said piston bore for passage therethrough and diverting the sand from the barrel bore. 

1. A pump comprising an elongated cylindrical barrel providing a fluid column confining and elevating cylinder, said barrel having a lower intake end provided with an attached foot valve, a plunger mounted for reciprocation in said cylinder, said plunger embodying a fluid column lifting piston slidingly operatively confined in the cylinder, a piston actuating rod reciprocable in said cylinder, said piston having a uniform axial bore extending therethrough and providing a fluid passage and being open at its lower inlet end and also at its upper discharge end, and a column lifting valve operatively mounted on the upper end of said piston, said lifting valve being communicable with the upper end of said passage, the lower end of said rod being operatively united with said lifting valve, and said lifting valve providing an operating joint between the rod and piston, said piston being of a transverse cross-sectional dimension that the outside diameter is just slightly less than the inside diameter of the bore of said barrel and has its peripheral surface in wiping contact with the encompassing wall of said barrel, whereby to obviate the need for packing rings on said peripheral surface, the entire lower end of said piston provided with a recess, said recess being truncated conical in form having its upper trunCated apical end merging communicably into the coacting lower end of said bore and providing a funnel-like pocket means for trapping and guiding a sand-laden fluid into said bore for passage therethrough and, in so doing, to minimize wear and tear on the cylinder and piston surfaces.
 2. The pump defined in and according to claim 1, and wherein said barrel, plunger and the operating joint are individually made of coacting plastic material.
 3. A pump comprising an elongated cylindrical barrel made of plastic material, the bore of said barrel providing a fluid column confining and elevating cylinder, said barrel having a lower end, an inlet valve assembly constituting a foot valve and removably fitted into and secured in place in said lower end, said valve embodying a plastic cup provided with an inlet orifice and having a captive ball check valve in the receptacle portion of the cup, a plunger mounted for receiprocation in said cylinder, said plunger embodying a plastic piston slidingly and operatively confined in the cylinder, also having a fluid passage, further having a reciprocating rod operable in the barrel bore, a coupling interposed between and connected to the rod and an upper end of the piston and having discharge ports and a hollow portion confining a ball check valve, said piston being elongated with its peripheral surface in sliding wiping contact with the wall of said cylinder and having a uniform axial open-ended bore comprising the fluid passage, the piston bore being open at its upper and lower ends, the upper end providing a seat, and the adjacent ball check valve being cooperable with said seat, and the lower end of said piston being provided with a truncated conical recess, the larger end of said recess opening through the bottom of said piston, the truncated upper end of said recess being communicable with the lower end portion of said bore and providing a funnel-like pocket means for trapping and guiding a sand-laden fluid into said piston bore for passage therethrough and diverting the sand from the barrel bore. 